Krajcova 2020 PLOS ONE

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Publications in the MiPMap
Krajฤovรก A, Urban T, Megvinet D, Waldauf P, Balรญk M, Hlaviฤka J, Budera P, Janouลกek L, Pokornรก E, Duลกka F (2020) High resolution respirometry to assess function of mitochondria in native homogenates of human heart muscle. PLOS ONE 15:e0226142. https://doi.org/10.1371/journal.pone.0226142

ยป PMID: 31940313 Open Access

Krajcova A, Urban T, Megvinet D, Waldauf P, Balik M, Hlavicka J, Budera P, Janousek L, Pokorna E, Duska F (2020) PLOS ONE

Abstract: Impaired myocardial bioenergetics is a hallmark of many cardiac diseases. There is a need of a simple and reproducible method of assessment of mitochondrial function from small human myocardial tissue samples. In this study we adopted high-resolution respirometry to homogenates of fresh human cardiac muscle and compared it with isolated mitochondria. We used atria resected during cardiac surgery (N = 18) and atria and left ventricles from brain-dead organ donors (N = 12). The protocol we developed consisting of two-step homogenization and exposure of 2.5 % homogenate in a respirometer to sequential addition of 2.5 mM malate, 15 mM glutamate, 2.5 mM ADP, 10 ฮผM cytochrome c, 10 mM succinate, 2.5 ฮผM oligomycin, 1.5 ฮผM FCCP, 3.5 ฮผM rotenone, 4 ฮผM antimycin and 1 mM KCN or 100 mM sodium azide. We found a linear dependence of oxygen consumption on oxygen concentration. This technique requires < 20 mg of myocardium and the preparation of the sample takes <20 min. Mitochondria in the homogenate, as compared to subsarcolemmal and interfibrillar isolated mitochondria, have comparable or better preserved integrity of outer mitochondrial membrane (increase of respiration after addition of cytochrome c is up to 11.7ยฑ1.8 % vs. 15.7ยฑ3.1 %, pห‚0.05 and 11.7ยฑ3.5 %, p = 0.99, resp.) and better efficiency of oxidative phosphorylation (respiratory control ratio = 3.65ยฑ0.5 vs. 3.04ยฑ0.27, pห‚0.01 and 2.65ยฑ0.17, pห‚0.0001, resp.). Results are reproducible with coefficient of variation between two duplicate measurements โ‰ค8% for all indices. We found that whereas atrial myocardium contains less mitochondria than the ventricle, atrial bioenergetic profiles are comparable to left ventricle. In conclusion, high-resolution respirometry has been adapted to homogenates of human cardiac muscle and shown to be reliable and reproducible.

โ€ข Bioblast editor: Gnaiger E โ€ข O2k-Network Lab: CZ Prague Krajcova A


Labels: MiParea: Respiration 

Stress:Cryopreservation  Organism: Human  Tissue;cell: Heart  Preparation: Homogenate, Isolated mitochondria 

Regulation: Oxygen kinetics  Coupling state: LEAK, OXPHOS, ET  Pathway: N, S, NS, ROX  HRR: Oxygraph-2k 

Alert2020, MitoFit 2021 PT, Etomoxir 

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